Haruo Sugi graduated from post-graduate school in the University of Tokyo with the degree of PhD in 1962, and appointed to be instructor in Physiology in the University of Tokyo Medical School. From 1965 to 1967, He worked at Columbia University as a research associate, and at National Institutes of Health as visiting scientist. From 1973 to 2004, He was Professor and Chairman in the Department of Physiology, Teikyo University Medical School.
From 1996 to 2006, he was also Chairman of Muscle Committee in the International Union of Physiological Sciences (IUPS). Sugi is now Emeritus Professor in Teikyo University.